# Limu (algae)

Limu, otherwise known as rimu, remu or ʻimu (from Proto-Austronesian *limut) is a general Polynesian term for edible plants living underwater, such as seaweed, or plants living near water, like algae. In Hawaii, there are approximately one hundred names for kinds of limu, sixty of which can be matched with scientific names. Hundreds of species of marine algae were once found in Hawaii. Many limu are edible, and used in the cuisine throughout most of Polynesia.

## Uses

Several species of limu are used as food throughout Polynesia and is typically eaten raw as accompaniment to meals, usually fish.
In Hawaii, limu was seen as a major component of the Hawaiian diet alongside fish and poi. Hawaiians cultivated several varieties of seaweed for food as well as to feed fish farmed within fish ponds. As many as 75 types of limu were used for food, more than the 35 used in Japanese cuisine, which is also well known for its use of seaweed. In modern times, limu is often used as a condiment, typically in raw fish dishes such as poke.
Limu was used in hoʻoponopono, the ancient Hawaiian process of conflict resolution. Injured and accused parties gathered to pray, seek forgiveness and eat limu kala leaves as a symbol of reconciliation. It is also used in traditional hula attire and as medicine.
Due to the shape of its foliage, the Maori also applied the name rimu to the native tree Dacrydium cupressinum.

## Types

Limu comes from multiple genera

### Cook Islands

| English name | Indigenous name |
| Crowned sea bells (Turbinaria ornata) | Remu taratara (Rarotonga and Mauke), Rimu taratara (Aitutaki), Limu (Pukapuka) |
| Double-edge sargassum (Sargassum aquifolium) | Rimu akau |
| Open-sponge seaweed (Hydroclathrus clathratus) | Remu oma (Rarotonga) |
| Sargassum obtusifolium (Sargassum obtusifolium) | Remu ʻūmoemoe (Rarotonga) |
| Sea grapes (Caulerpa racemosa) | Remu kai (Rarotonga and Mauke), Remu kōnini (Mangaia), Rimu kai (Aitutaki) |
| Turkeytail seaweed (Padina boryana) | Remu taʻiriʻiri (Rarotonga) |

### Easter Island

| Image | English name | Indigenous name | Description and use |
| | Dictyopteris australis (Dictyopteris australis) | Auke | |
| | Sargassum obtusifolium (Sargassum obtusifolium) | Miritoni | |

### French Polynesia

| English name | Indigenous name |
| Cactus tree alga (Caulerpa cupressoides) | Mamaʻga (Rapan) |
| Chnoospora minima (Chnoospora minima) | Imu keikei aoa (Marquesan) |
| Cladophora patentiramea (Cladophora patentiramea) | Imu ouoho (Marquesan) |
| Gracilaria (Gracilaria) | Remu ʻura (Tahitian) |
| Grass kelp (Enteromorpha flexuosa) | Imu vai (Marquesan) |
| Green sea cushion (Codium arabicum) | Imu tutae kioe (Marquesan) |
| Sea grapes (Caulerpa racemosa) | ʻonini (Tahitian), Imu topua (Marquesan), Remu vine (Austral), Konini (Rapan) |
| Sea lettuce (Ulva lactuca) | Rimu miti (Tahitian), Imu kokuu (Marquesan) |

### Hawaii

| English name | Indigenous name | Description and use |
| Antler seaweed (Codium reediae) | Limu aʻalaʻula | |
| Branched sea cushion (Codium edule) | Limu wawaeʻiole | Meaning "rat's foot seaweed" |
| Branched string lettuce (Ulva prolifera) | Limu ʻeleʻele | |
| Champia (Champia) | Limu ʻoʻolu | Meaning "thin seaweed". Shares its name to the similarly used species Chondria tenuissima. |
| Chondria tenuissima (Chondria tenuissima) | Limu ʻoʻolu | Meaning "thin seaweed". Shares its name to the similarly used Champia seaweeds. |
| Chylocladia (Chylocladia) | Limu akuila, Limu kihe | |
| Crowned sea bells (Turbinaria ornata) | Limu kahili | |
| Dictyopteris (Dictyopteris) | Limu lipoa | Meaning "seaweed gathered from the deep" referring to its habitat of growing in deep water. The species Dictyopteris australis and Dictyopteris plagiogramma were gathered as food. |
| Dictyota (Dictyota) | Limu alani | Meaning "bitter seaweed" |
| Double-edge sargassum (Sargassum aquifolium) | Limu kala | Meaning "forgiving seaweed" employed during hoʻoponopono. |
| Grateloupia filicina (Grateloupia filicina) | Limu huluhuluwaena | or "pubic hair") – favorite of Liliʻuokalani. |
| Gelidium (Gelidium) | Limu loloa | Meaning "long or slender seaweed" |
| Griffithsia (Griffithsia) | Moʻopunaakalīpoa, Moʻopuna | |
| Gymnogongrus (Gymnogongrus) | Limu koele | Meaning "dry or hard seaweed" |
| Halymenia formosa (Halymenia formosa) | Lepelepe-o-Hina | shawl of the goddess Hina. Shares its name with a native butterfly and a family of nudibranchs. |
| Laurencia nidifica (Laurencia nidifica) | Limu maneʻoneʻo | |
| Laver (Porphyra) | Limu luau, Lipaheʻe | |
| Martensia fragilis (Martensia fragilis) | Limu haʻula | |
| Ogo (Gracilaria coronopifolia) | Limu manauea | cooked with meats to form a savory jelly. Later diced raw with poke, mixed with chili and salt. |
| Polysiphonia (Polysiphonia) | Limu hāwane | |
| Red sea plume (Asparagopsis taxiformis) | Limu kohu | Meaning "supreme seaweed" |
| Sailor’s eye (Valonia utricularis) | Limu lipuʻupuʻu | |
| Sea lettuce (Ulva lactuca) | Limu palahalaha, Pakaiea | named after a shark god who was swaddled in its silken leaves. used in hula |
| Spyridia spinella (Spyridia spinella) | Limu hulu puaʻa | |
| Tattered sea moss (Hypnea) | Limu hina | |
| Tuffed seaweed (Ahnfeltiopsis concinna) | Limu ʻakiʻaki | |

### New Zealand

| English name | Indigenous name | Description and use |
| Bubble caulerpa (Caulerpa sedoides) | Rimurimu | |
| Carrageenan weed (Gigartina) | Rehia, Rimurehia | |
| Clymene (Clymene) | Karengo, Kareko, Parengo, Reporepo | |
| Eelgrass (Zostera) | Karepō, Nana | |
| Gracilaria (Gracilaria) | | |
| Kelp (Laminariales) | Pakake, Pakaka | |
| Laver (Porphyra) | Karengo, Kareko, Parengo, Reporepo | Originally, Karengo was used to describe seaweed belonging to the Porphyra genus. Recent genomic analysis however has Karengo cover more than 30 species belonging to genus Porphyra, Pyropia, Clymene and Lysithea. |
| Lysithea (Lysithea) | Karengo, Kareko, Parengo, Reporepo | |
| Neptune’s necklace (Hormosira banksii) | Koiri | |
| Sea lettuce (Ulva lactuca) | Rimu kaikai | |
| Sea rimu (Caulerpa brownii) | Rimurimu | |
| Southern bull kelp (Durvillaea) | Rimurapa, Rimuroa, Kōauau | |
| Southern laver (Pyropia) | Karengo, Kareko, Parengo, Reporepo | |

### Niue

| Image | English name | Indigenous name | Description and use |
| | Cactus tree alga (Caulerpa cupressoides) | Limu tahi | |
| | Sea grapes (Caulerpa racemosa) | Limu fua | |

### Samoa

| English name | Indigenous name |
| Crowned sea bells (Turbinaria ornata) | Limu lautalatala |
| Gracilaria (Gracilaria) | Limu aau |
| Halymenia (Halymenia) | A ʻau |
| Sargassum (Sargassum) | Limu vavoa |
| Sea grapes (Caulerpa racemosa) | Fuafua |
| Turkeytail seaweed (Padina boryana) | Limu lautaliga |

### Tonga

| English name | Indigenous name |
| Cactus tree alga (Caulerpa cupressoides) | Kaka |
| Cladosiphon (Cladosiphon) | Tangaʻu |
| Flat-top sea grape (Caulerpa peltata) | Fuofua |
| Green feather algae (Caulerpa sertularioides) | Louniu, Louango, Tuʻaniu |
| Hypnea charoides (Hypnea charoides) | Limu vai |
| Scalpel green seaweed (Caulerpa scalpelliformis) | Palalafa |
| Sea grapes (Caulerpa racemosa) | Toke, Fuofua, Alako, Teʻemoa, Teʻepuaka |
| Serrated green seaweed (Caulerpa serrulata) | Kaka |

### Tuvalu

| Image | English name | Indigenous name | Description and use |
| | Sea grapes (Caulerpa racemosa) | Limu pukupuku | |

## Threats

Limu has become increasingly difficult to find because of over-picking, pollution, and urban development, especially construction in watersheds. Many important kinds of limu grow best in brackish water where fresh water empties into the sea. Another threat to limu is the spread of marine alien invasive species, such as members of the genus Kappaphycus (smothering seaweed), Gracilaria salicornia (gorilla ogo), Avrainvillea amadelpha (leather mudweed), Hypnea musciformis (hook weed) and Acanthophora spicifera (prickly seaweed).